Distributing device for tobacco and the like



June 17, 1969 F. BoNNRlc 3,450,311

DISTRIBUTING DEVICE FOR TOBACCO AND THE LIKE Filed March 13, 1967 INVENTQK Emu/Mp5 Amon/ f5,2 SPA Ammf United States Patent O U.S. Cl. 222-280 9 Claims ABSTRACT OF THE DISCLOSURE A distributing device for tobacco for permitting the uniform supply of processing -machines with a continuous ow of material which has a contant bulk density without damaging the material. A duct composed of a series of sections, the cross sections of the sections decreasing in consecutive order, and paddle wheel carrying drums rotatably located in shoulders in each one of the sections, which drums are rotated with speeds increasing from one to the other successive section.

The formation of a continuous stream of librous and compressible materials in a uniform ow presents problems which are made even more diicult in the case of material such as shredded tobacco which is both delicate and intermingled. This material has a tendency to break up and lose its cohesion when regulating devices such as cards are employed. It also has a tendency to collect into lumps if the devices employed have the effect of com pressing it.

The main object of the present invention is to permit the uniform supply of processing machines with a continuous flow of material having a predetermined shape .and constant bulk density without causing degradation of said material.

It is known to employ for the supply of tobacco torreers vertical ducts of rectangular cross-section, two opposite walls of which are provided in symmetrical manner with a semi-cylindrical bulge so dimensioned that the cross-section of the duct is doubled in the horizontal plane which passes through the axes of said walls. Two paddle wheels are -mounted coaxially with said lbulges and rotate at the same speed in opposite directions. The extremities of the paddles sweep the internal faces of the bulges and the cylinders of revolution are tangent to each other in the axis of the duct. It is understood that the material which is fed into the top of the duct is intended to ll the buckets formed by the paddles and is delivered downwards with a uniformity which is better than at the inlet.

The elements of the apparatus according to the invention make profitable use of the regulating action of this design by associating it with devices which produce action on the flow rate according to forms of construction which cause the material conveyed to form a stream of smaller cross-sectional area from the upstream end to the downstream end of the machine. It is readily apparent that, in order to prevent packing of the material, it is advisable to ensure that these devices impart to the stream of material an additional speed in proportion to the reduction in cross-sectional area. Broadly speaking, it is within the field of the invention to associate with means for reducing the cross-sectional area of tlow of a stream of material devices for the purpose of accelerating said stream of material in such a manner as to maintain a volume rate of ow which is at least equal.

According to the generalA process of the invention, the stream can follow a passageway which is open on one or Patented June 17, 1969 ice a number of sides or a closed duct. In the case of a passageway, the shaping-of the stream can be effected at the sides, the devices employed for increasing the speed being, for example, endless belts or alternatively cylinders which work at a more or less substantial depth within the stream.

In a preferred embodiment of the invention, the material is transported in a duct composed of a series of segments of constant cross-section which are joined by reduction zones in which the devices for accelerating material are placed.

The devices referred-to can be constituted by one or a plurality of drums rotatable about their axes and adapted to carry active elements which sweep in counterflow to the main stream those sectors of the reduction zones which do not open into the downstream duct segment, thereby redirecting the material towards the reduced stream. The active elements will be in the form of teeth or paddles depending on the type of material conveyed and on the secondary effect desired. In the case of fragile and interlaced material, paddles fitted at their extremities with a exible and smooth blade of molded polyamide, for example, 'are particularly well suited to the purpose. It will be understood that the entire paddle can be similarly fabricated of the same material.

The axis of each rotary drum or paddle wheel of the type referred-to could be substantially perpendicular t0 the general direction of the stream. Provision can be made in a given reduction zone, for example, for two paddle wheels which are adapted to rotate in opposite directions and housed in two oppositely-facing shouldered portions. The active elements of these paddle wheels can be adapted to intersect in the central portion of the stream if they rotate at the same angular velocity. However, degradation of material will be reduced by assigning to each paddle wheel a separate work sector which will always comprise practically the entire volume of the shouldered portion. A standard assembly consists of two identical paddle wheels having parallel axes and adapted to rotate at the same speed in opposite directions, the active elements of said paddle wheels being adapted to describe two surfaces of revolution which are tangent to each other and which closely conform to the shells constituting the shouldered portions. l

In constructional assemblies of this type, the rotary paddle wheels have `a tendency, as mentioned earlier, of returning in counterflow to the main stream that part Of the material which flows towards the shouldered portions. In order to permit these movements and to` prevent packing between two reduction zones, it is advantageous to impart to the acceleration units a speed which is slightly higher than that which is strictly made necessary by the reduction in cross-sectional area of the duct. For the same reason, it is also necessary to ensure regularized supply to the first reduction stage. In this type of construction, one homogeneous solution consists in providing at the head of the apparatus a supply duct of similar design to the ducts described above in reference to tobacco torrefiers.

With the same object in mind, and in odrer to prevent the degrading action of the rotary paddle wheels on the long fibers of material which might otherwise be carried along by the units of two different stages, it is an advantage to make provision between these latter for duct segments which can be of constant cross-section and of suitable length for this purpose.

In an apparatus which is made up of a number of crosssectional-reduction stages each comprising a set of rotary paddle wheels, the volume rate of ilow is caused to vary by either increasing or reducing the'angular velocity of all the paddle wheels in the same ratio. It will therefore be an advantage to drive said paddle wheels from a single motor. On the other hand, in order to modify the speed of the set of rotary paddle wheels of one stage as a function of the supplied data relating to the filling of duct sections either upstream or downstream, it is advisable to provide for each set of paddle wheels control devices which can be disconnected from the others. The data referred-to above can be supplied either by photoelectric detectors or by micro-switches which are responsive to the pressure exerted by the material on a predetermined sector of the walls.

The following exmaple illustrates one possible form of embodiment of an apparatus for distributing cut tobacco as contemplated by the invention. fIt will be understood that this embodiment is not given in any sense by way of limitation but that original features can become apparent from the description and accompanying drawings, in which:

FIG. l is a cross-sectional view .of the apparatus on a rst vertical plane of symmetry;

|FIG. 2 is another cross-sectional view of the apparatus on a second vertical plane of symmetry at right angles to the iirst.

In these two views, those elements which are sufciently well dened in one ligure are represented in the other only by their axes.

The apparatus is essentially composed of a hollow body -1, all the horizontal cross-sections of which are rectangular. Said body is shown to be mainly constructed in the form of a stack of vertical-walled duct segments Z, 3, 4, 5, 6 which are joined to each other by quartercylinder sectors 7, 7', 8, 8', 9, 9', 10, 10'. Two of the opposite 'walls of two adjacent duct segments are always located in the same plane. However, one of the dimensions of the lower duct segment is only one-half the corresponding dimension of the upper duct segment. Thus, the duct segments 2 and 3 have the same depth in the plane of FIG. l but the width of the duct segment 2 is twice that of the duct segment 3. The duct segments 4 and 5 have the same width in this figure plane but the depth of the duct segment is one-half the width of the duct segment 4.

Provision is made in the top portion of the duct segment 1 for two semi-cylindrical bulges 11 and 11 having a horizontal axis and a diameter correspondingto the width of the adjacent wall. Two paddle wheels 12 and 12' are rotatably mounted within said bulges; the rotational axes 13 and 13 of said wheels are therefore located in the plane of the bulged walls and the paddles are adapted to skim over the internal surfaces of said walls as they move in rotation.

Furthermore, each junction zone 7, 7', 8, 8', 9, 9', 10,

10' is fitted with a similar wheel 14, 14', 16, 16', 18, 18', 20, 20' having a horizontal axis 15, 15', 17, 17', 19, 19', 21, 21'. The rotational axis of a wheel is located in the line of extension of the plane of the wall of the downstream portion of the duct.

The dimensions of the wheels 14, 14', 16, 16', 18, 18', 20, 20' are such that each set of two wheels sweeps the entire junction zone between two duct segments.

The Wheels of a same set rotate at the same speed and in opposite directions. The recesses formed between their paddles are displaced by one-eighth of a revolution from one wheel to the next in order that they should not discharge material at the same time and in order to prevent any shearing of material.

If the speed of rotation of the wheels 12 and 12' is n, the speed adopted for the wheels 14 and 14 will correspond to a value which is higher than 2n such as, for example, 3n. The speed of the wheels 16 and 16' will be 9u and so forth up to the wheels 20 and 20' which will rotate at a speed of 81n.

The operation of an apparatus of this type can readily be understood and is clearly brought out by the foregoing description. Cut tobacco which is fed in a fairly uniform manner into the top of the body 1 will be returned to the duct segment 2 by the paddle wheels 12 and 12' with greater uniformity. The wheels 14 and 14 will increase the velocity of falling motion of the tobacco so that the duct segment 2 will never be choked and will accordingly permit of variation in the level of tobacco. The same process will take place from one duct segment to the next and the wheels 20 and 20' will deliver at the outlet a uniform flow of tobacco which has the desired crosssectional area and which has sustained only the minimum amount of degradation.

The starting or stopping of either all or some of the paddle wheels 12-14-16-18 and 20 can be performed either by means of photoelectric cells which react to the presence or absence of material within one of the duct segments 2-3-4-5-6 or by means of micro-switches which react to the pressure exerted by the material on the walls of said duct segments; said micro-switches can evidently be replaced by any other suitable detector element which is responsive to the lling density at the level of said element.

One application of an apparatus which is cited by way of example and controlled in the manner described above is carried into effect in the machine for dosing cut tobacco which forms the subject of French Patent No. 1,395,611. The passageway 6 is equipped at its base with a volumetric device which forms predoses. The uniformity of these predoses depends on the regularity of filling of the passageway 6. This filling is detected by a series of photoelectric cells which serve as markers along one of the vertical walls of said passageway. The data supplied by said photoelectric cells are collected in an AND or an OR logic circuit, depending on the type of control system adopted. The output signal of this circuit initiates the start-up of the complete assembly of paddle wheels 12, 14, 16, 18 and 20 and the stopping of the single wheel 2.0. The stoppage of the wheels 12, 14, 16 and 18 is controlled by a photoelectric cell which detects either the presence or absence of cut tobacco in the passageway 4 so that a continuous supply to the wheel 20 is always ensured.

What I claim is:

1. In a distributor of the type wherein solid material in a divided state such as tobacco in the form of shreads or fragments as supplied at the feed end of said distributor in an inhomogeneous stream is delivered at the product end thereof in a uniform stream of predetermined cross-section and of the type comprising a duct having a feed end and a delivery end; at least two successive zones corresponding to a reduction in transverse cross-section and a rotary device for accelerating the stream located in each of said zones inside said duct, each of said devices comprising a paddle wheel having paddles of exible mterial, the spaces swept by said devices having transverse cross-sections which decrease when passing from the upstream one to the downstream one of two successive devices.

2. In a distributor according to claim 1, wherein said rotary devices are entirely within said ducts and have speeds which increase when passing from the upstream one to the downstream one of each pair of successive devices, the ratio between the speed of the downstream one and the speed of the upstream one being higher than the ratio between the cross-sections of the corresponding upstream and downstream zones.

3. In a distributor according to claim 1, wherein said zones of reduction in transverse cross-section constitute shouldered portions of the duct, said rotary devices being entirely within said ducts and being mounted in said shouldered portions.

4. In a distributor according to claim 3, wherein said spaces swept by said rotary devices are partially enclosed by the internal surface of said duct constituting said shouldered portions.

5. In a distributor according to claim 3, wherein said duct comprises at each zone of reduction in transverse cross-section two shouldered portions which are in oppositely-facing relation and a rotary device mounted in each of said shouldered portions, each adapted to rotate in a direction opposite to the `direction of rotation of the oppositely facing one.

6. In a distributor according to claim 1, wherein said rotary devices are entirely within said ducts and said transverse cross-sections of said duct have a substantially rectangular shape.

7. In a distributor according to claim 6, wherein each reduction of section is the result of the reduction of only one of the dimensions of said rectangular shape.

8. In a distributor according t claim 1, wherein said duct is symmetrical with respect to the axis thereof.

9. In a distributor of the type wherein solid material in a divided state such as tobacco in the form of shreds or fragments as supplied at the feed end of said distributor in an inhomogeneous stream is delivered at the product end thereof in a uniform stream of predetermined cross-section and of the type comprising a duct having a feed end and a delivery end; at least two successive Zones corresponding to a reduction in transverse cross section and a rotary device for accelerating the stream located in each of said zones inside said duct, the spaces swept by said devices having transverse cross-sections'which decrease when passing from the upstream one to the downstream one of two successive devices, said rotary devices 4being entirely within said ducts and having speeds which increase when passing from the upstream one to the downstream one of each pair of successive devices, the ratio between the speed of the downstream one and the speed of the upstream one being higher than the ratio between the cross-sections of the corresponding upstream and downstream zones, said zones of reduction in transverse cross-section constituting shouldered portions of the duct, said rotary devices being mounted in said shouldered portions, said spaces swept by said rotary `devices being partially enclosed by the internal surface of said duct constituting said shouldered portions, said duct comprising at each zone of reduction in transverse cross-section two shouldered portions which are in oppositely-facing relation and a rotary device mounted in each of said shouldered portions, each adapted to rotate in a direction opposite to the direction of rotation of the oppositely-facing one.

References Cited UNITED STATES PATENTS 848,343 3/1907 Brown et al. 230-125 1,483,703 2/ 1924 Wever 221-281 X 1,623,650 4/ 1927 Anderson 230-125 3,145,426 8/1964 Hijiya et al. 3,284,140 11/ 1966 Reiterer 302-28 X ANDRES H. NIELSEN, Primary Examiner.

U.S C1. X.R. 

